gbproxy: Properly capture HDLC/FR traffic in addition to ethernet

We cannot use "-i all" but must list each interface separately,
which is only supported by dumpcap.  We also must write pcapng
files.

Change-Id: Id412af3bb6bcad5e0f2cf40a6dc497d7e4f3d948
diff --git a/gbproxy/GBProxy_Tests.default b/gbproxy/GBProxy_Tests.default
index 799ac32..8634b49 100644
--- a/gbproxy/GBProxy_Tests.default
+++ b/gbproxy/GBProxy_Tests.default
@@ -1,3 +1,7 @@
+[DEFINE]
+TCPDUMP_START := $TTCN3_HACKS_PATH"/ttcn3-dumpcap-start.sh"
+TCPDUMP_STOP := $TTCN3_HACKS_PATH"/ttcn3-dumpcap-stop.sh"
+
 [LOGGING]
 FileMask := LOG_ALL | TTCN_MATCHING;